Background: Ukraine is the epicenter of HIV/AIDS in Eastern and Western Europe, with an estimated 230,000 infected, most of whom are injection drug users (IDUs). The goal of this project is to compare the effectiveness of two interventions in reducing the spread of HIV infection in three Ukrainian locations noted for their high HIV seroprevalence: Kiev, Odessa and Makeevka/Donetsk. The interventions include the HIV Counseling and Education (C & E) intervention model developed during NIDA's Cooperative Agreement and the Indigenous Leader Outreach Model (ILOM). Aims: To compare the relative effectiveness of the two approaches in: 1) increasing knowledge about HIV and AIDS transmission; 2) increasing self-efficacy to practice safer drug and sex HIVor related behaviors and motivation to quit drug use; and 3) decreasing or eliminating injection drug use and reducing HIV-related drug and sex risk behaviors. Other aims are: 4) to evaluate differences between individuals who are HIV positive and those who are HIV negative in decreasing or eliminating injection drug use and reducing HIV-related drug and sex risk behaviors within each intervention (ILOM and ILOM+C & E) and across interventions as appropriate; and 5) to assess factors associated with reduced injection drug use and reduced HIV-related drug and sex risk behaviors. Based on the success of this effort, it is our long-term goal that at least one of these interventions will be sustained by the government of Ukraine following the conclusion of the research. Methods: In collaboration with Dr. Sergiy Dvoryak and the Directors of three nongovernmental organizations, 600 IDUs from each of the three cities will receive the C & E intervention or the C & E plus the ILOM, using a crossover experimental design. Subjects will be recruited through street outreach, interviewed, intervened with and followed at six and 12 months. Subjects in both arms will be offered HIV testing and counseling (using the C & E model) following the baseline interview and at both follow-up assessments. Using mixed model analysis of variance and logistic regressions accounting for the relatedness of repeated measures on each subject, analyses will assess the extent to which the C & E alone and the C & E plus the ILOM, as well as other factors, are effective in increasing knowledge, self-efficacy, motivation and reducing risk behaviors associated with HIV. Analyses will also evaluate differences between IDUs who are HIV infected (estimated at 42%) and those who are not infected. [unreadable] [unreadable]